The difference between an attribute and a feature depends on the product itself. Some products might share the same property, one being an attribute built for building product variations, another one being simply an invariable feature. For instance, a customer can buy an iPad variation based on attributes (color, disk space) but not on features (weight, size).

Likewise, another shop might sell t-shirts variations based on attributes (color, size, gender) but not on features (weight). In your shop, features are displayed in a table, giving additional information about the product; while attributes make it possible to select among product combinations.